Photovoltaic cell



Nov. 15, 1932. s. WEIN 1,887,531

' PHoTovoLTAIc CELL,

Filed July 51, '1928 2 Sheets-Sheet. 1

Nov. 15, 1932. s. WEIN 1,887,531

PHoTovomnAIc CELL Filed July '31, 1928 2 sheets-sheet 2 jects of my invention -much the same as that Paten-tea Nov. is, 1932 SAMUEL WEIN, 0F. NEW YORK, N. Y., .ASSIGNOB TQ NEW YORK, N. Y., A CORPORATION mmrovrsroN coarona'iIoN, or or 'NEW Yonx PHOTO'VOLTAIC CELL Application led July `3,1,

My invention relates to improvements in electrical apparatus, andmore particularly relates to an improved photo voltaic cell, and the method of making same. One of the obis to produce a highly sensitive photo voltaic cell, one particularly eicient to the light radiations, and giving rise to greater potentialsl as a result of subjecting the new form of light sensitive cell to a source of light. Because of these features, my cell is particularly applicable'to the various electrical devices in which a light sensitive cell is an integral part in its circuit,

and specifically to the transmission of photographs, facsimiles and the like, and to socalled television systems wherein it is essential to employ a highly'eicient cell with re spect to light sensitiveness and current output. Other uses to which my invention mayv e applied are-the photographic recording and reproduction of sounds,'direct reading ce photometry, variations in cell. l v l In order that my invention may be properp ly understood, Kit is necessary to point out that the generic term photo electric or light sensitive or photo sensitive cell includes several typesof cells differing widely not only in construction but in theory of operation.

The well known selenium cell is a resistance which varies with the impressed light.

The photo electric cell, consistin of two elements in a highly evacuated cham r, op erates by reason of electron How from an alkali metal or its correspondin hydride or oxide, the change in the rate 0% flow bein proportional to the impressed light within certainlimits. The theory of operation is relating'to the ilow of electrons from the filament to the'plate in thi);e ordinary two orthree element vacuum tu 1 Another class of light sensitive cell is that in which a filament, a plate anda collector are sealed in an evacuated vessel, the plate being made photo sensitive. An example of this construction would be an ordinary three element vacuum tube having the plate coated actuating electrical circuits by light falling on the photo voltaic 1928.` Serial No. 296,510.

with a suitable metal oxide; here the' id` y would function as a collector of photo e ec-I trons and not as a modulator. In this type of cell electrons are disassociated from the metal plate by electronic bombardment from the filament, the photo electron emission from vthe late being proportional to theamount utilizes the Becquerel effect produced by light falling upon an electrode immersed in a suitv able electrol Inthis cell the chemical action is' accelerated in the presence of light and therefore any chemical action which is accelerated in the presence of light may be used to bring about this result. -A cell of this tye I have designated as a photo voltaic While the Becquerel effect has been known for many years and while man attempts have been made to utilize this in t e commercial production of light sensitive cells, the physlcal proportions tion necessary to produce a rigid commercial structure that would withstand handling and use, and the various combinations of elec-j trolyte and electrodes to produce a commercially usable device have not heretofore been known, Cells heretofore using this effect have been merely laboratory experiments incapable of commercial use.

Accordingly I herein disclose anew and in of the cell, the construcuseful combination of elements constituting a commercial form times more eiiicient than hereto'- Jtrated ,inf Figures 6, 7, 8 and 9 `:wherein isr -spaced metal plates with terminals p of cell that can be easily g Y and cheaply produced in large quantities and Which utilizes the Becquerel eiiect in a man-j @gradis I convert to cuprous oxid 65 bodied in ai shown in addition to the above features, a 'made of a plurality of convolutions o wire upon a sup ort and aixed between `'the metal plates. T e primar object of this to secure control of t e potential as generated in ythe photo voltaic cell when exposed toa source of light, thus making the cell applicable for other purposes well known to those familiar with the art.

Referring to the drawings, the numeral 1 desi ates a transparent glass envelope. Varlous kinds of glass may be used and different types of glam will give different results, for instance, lead glass bein much more opaque to the higher li ht ra iations, will invariably produce a ce less sensitive because less actinic light can pass it; lime glass will produce a cell of greater sensitivity and resulting greater current output because itis much more transparent than is lead glass. This is also the case with Pyrex glass, Aand particularly is the case with quartz. In other words, ent the glass to higher light radiations, the

is so ex ensive, a cellmay be constructed with a c eaper grade of glass having sealed therein a window of quartz of suitable size the sealing between the poorer and shape; (girade o glass and the quartz window be 111g one by means of graded glasses and fluxes to facilitate this sealing between the higher sealing glass to the lower sealing glass.

The transparent glass envelope designated as 1 in the drawings for` best results should have all its surface painted over except s uch portions as serve as windows Mto admit llght to the metal plates. The paint employed for this purpose may filter oi the'unwantedrays which of course, adds to the all-around eiiiciency of the cell. In the preferred form of my invention, all the metal parts are the same metal, e. g., copper; other metals may be used, suclnas nickel, platinum, gold, silver, etc., withvarious lmg of oxides and the halides thereof.

I find good results are secured by means of .the foregoing mechanical construction, using at least of which e, and insert Ain an copper plates the surfaces electrolyte of copper sulphate, potassium chloride, or potassium sulphate.

Prior to forming the cuprous oxide lm by any well lmown process, I irst clean. the copper plate in any Voo mmon'manner, as by means of boiling it in water, with a little alkali in it or steeping the plate infa strong nitric acid, solution, thereafter washingin running water to ree `the copper plate om free acid or alkali orrea formed on the plates during process.

By Way de I shall now describe the same as emdevice` suitable giors many uses the cleaning of illustrating my invention in the more transpar-4 more eiiicient will the cell be. Since quartz be of such material as tov tion products ables the space a Figure 1;

Figure 5, Figure 3;

Figure 6 is a sectional view of a modiiied form of the cell, Figure 1; containing a grid element and with one of the plates or ele trodes removed to lshow the grid Figure 7 is a sectional view on the line 7, 7, of Fig. 6;

5 is a sectional view on the line 5,

Figure 8 is a sectional view on the line 8, 8,

Figure 9 is a bottom view showing-the terminals of the cell, Figure 6.

lThe numeral 1 designates a transparent .glass envelope which may be of .any size, shape and form having a re-entrant stem 10a and two glass tubes 2 and 2a, into which are sealed two wires 7 and 7a. These wires may be of platinum, copper clad, dumet pr other similar wires. The principal supports or side rods 6 and 9 for the copper plates 5 and 5a are made of large gauge wirewhlch support the insulators or cross members 4 and 4a being secured thereto by wires 14. The assembly comprising the support 6 and 9 and the insulators 4 and 4a (preferably of glass form a frame to which is fastened the meta plates or electrodes 5 and 5a, held in position by means of thewire hooks 15 supported in the insulators 4, 4a, the set of hooks for one plate being out of contact with those of the other plate. These sealedin the insulators. Electrical contact is establishedP to the metal plates 5 and 5a by means of the wires 7 and 7a which pass through the glass rods 2 and 2a through the re-entrant stem 10a and terminate in the base 3 at the terminals or plugs 7 7 The plate assembly containing the plates or electrodes properly and rigidly' spaced apart the required distance includes a frame composed of supports 6.,` 9 and insulators 4, 4a. This is secured within the container or envelope 1 byv providing the adjustable clamp member 8 attached to supports 6, 9,

which clamp -is secured tothe re-entrant stem 10a in any suitable manner, such as by bolt 10 and nut 11. This assembly may be further stiened by providing the stiien'ing rod or extension a mounted upon the stem-10a and passing through insulator 4 intoinsulator 4a. This tends to. prevent vibrationof the asf sembly within the container and also enbetween the edges of the hooks may be insulators and plates Vand the wall ofthe container 1 to bemore accurately maintained.

a glass bead which is fused\to the insulatorl support 4a. The other-end of said grid element ames througha glass bead which is fuseI to the insulator support 4 and continue `through insulator support 4 and glass rod ,ljbfterminating in the base 3 at the plug or terminal 13a. l

The characteristicsof my voltaic cell can be varied by spacing of' the metal plates 5 and 5a. The closer together the metal plates 5 and adzhe lower will be the internal resistance of `the photo voltaic cell. For cells I 'requiringa high internal resistance the metal plates 5 and 5a may have a greater separation, which can be obtained by using insulator supports 4 and 4a of a greater width. The Ainternal resistance of the photo voltaic cell may alsobe changed by using an electrolyte of higher or lower concentration.

I electrolyze the cleaned copper plates 5 and 5a in a 10 per cent sodium chloride (salt) solution only for a few minutes, and to these cleaned copper plates is attached a concictor thereby electrically connecting them together. The plates are then connected to the cathode of a source of direct current, and a copper anode, connected with the source of direct current is also placed in the solution. I find that the best electrolyzing potential is between 2 and 10 volts, and 3 to 10 ampere's per square decimeter. copper plate a homogenous film of cupric the salt solution and place it in hot water,

hydrolyzing the cupric chloride to form cuprous chloride which in turn is hydrolized toY form cuprous oxide, the most sensitive form of element for the photo voltaic cell.

It is obvious, that a plurality of cleaned plates may be electrolyzed at one time so as to obtainplates that under the same conditions, will give the same results.

The copper plates with the film of cuprous oxide are now assembled as shown inthe drawings, and the transparent bulb or en v suitable I now form on thechloride, I now remove this copper plate from bein Obviousl light of di erent frequencies and the resultant current obtained from-thecell will be modulated accordingl and will be a component of the currents-t at would be. produced by'each frequency alone.

By using both plates and the grid I obtain vanother and different combination of results and lay-impressing. byaany known means a potential on the grid, I can vary the character of the/current obtained Afrom the cell within wide limits both as to current, potential and frequency. y

As the circuits-employed to obtained these results are well known and mayr be any of those employed in connection with vacuum tubes, amplifiers and the like, I do not describe the same in detail.

It is to be understood that the invention is not limited to Ithe preciseconstruction set forth but that it includes within its purview whatever changes fairly come withinleither the terms or the s'pirit of the appended claims.

Having described my invention, what lI claim is: D

1. A photo voltaic celL comprising -two metal electrodes, equally spaced, a wire grid interposed between the two metal electrdes, said wire rid and two metal electrodes in contact wit parent glass envelope. v

2. A photo voltaic cell comprising two metal electrodes spaced apart by means of insulating material, awire grid interposed between and insulated from the said electrodes having electric conductors ,brought out through a base, said base supporting a glass envelopel filled with a normal solution of copper sulphate, and said metal plates and wire rid being immersed in said solution.

3. trodes spaced apart by means material and one of said electrodes comprising a coating of cuprous oxide, a grid interposed between and insulated from the said electrodes having electric conductors brought out through a base, said base supporting a glass envelope lled with asolution of co per sulphate, and saidi'metal plates and grld immersed in said solution. Y

4. n a photo voltaic cell, an electrode supporting structure com rising a pair of longitudinal metallic mem rs, lateral insulating members carried by said longitudinal members, electrodes su ported by said lateral members, a third e ectrode supported thereby and electrolyte in contact vwith said electrodes.

5. In a photo voltaic cell, an electrode supporting structure comprising a pair of longi- Vtudinal metallic members, members carriedZ by said longitudinal mem\ bers, electrodes supported by said lateral members, a third electrode supported between lateral insulating I may employ twovsources of an electrolytetin a sealed transphoto voltaic cell comprising two elecy of lnsulating -'4- 'mausi' said first electrodes, andv electrolyte in contact with said electrodes. 6. In a photo voltaic cell comprising an envelope containing. a pair of electrodes immersed in electrolyte,` amodulatingelement -disposed between adjacentsurfaces of the electrodes.

7. In a photo voltaic cell comprising s sealed envelope containing apair of electrodes in contact with electrolyte, a modulatin element adjacent said electrodes, and circuit connections from said electrodes and element leadin outside said envelope. Signed at ew York in the county of New Y York and State of New York this thirtieth day ofJuly, A. D. '1928.

SAMUEL WNj 

